JP2016143415A - Apparatus and terminal block to communicatively couple three-wire field devices to controllers in process control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an example apparatus to communicatively couple three-wire field devices to controllers in a process control system.SOLUTION: An example terminal block 300 is disclosed that includes a first interface having three termination points 306 to terminate each of three wires from a three-wire field device 502. The example terminal block further includes a second interface to removably receive a first termination module 124a that is to communicate with the three-wire field device using a first communication protocol and to communicate with a controller via a shared bus of a termination panel using a second communication protocol different than the first communication protocol.SELECTED DRAWING: Figure 5

Description

  The present disclosure relates generally to process control systems, and more particularly to an apparatus for communicatively connecting a three-wire field device to a controller in a process control system.

  Process control systems, such as those used in chemical, petroleum, pharmaceutical, pulp and paper, or other manufacturing processes, typically to at least one host including at least one operator workstation and analog, digital, or analog and digital Includes one or more process control devices communicatively connected to one or more field devices configured to communicate via a combined communication protocol. Field devices, which may be device controllers, valves, valve actuators, valve positioners, switches and transmitters (eg, temperature, pressure, flow rate and chemical component sensors) or combinations thereof, include open or closed valves and measurement or estimation processes Functions within the process control system such as parameters. The process control apparatus receives a signal indicating process measurement issued by the field device and / or other information related to the field device, implements a control routine using this information, and further generates a control signal. Further, the control signal is transmitted to the field device through a bus or other communication line to control the operation of the process control system.

  The process control system provides a number of different functions and can be used to-to-point (eg, one field device communicatively connected to a field device bus) or multidrop (eg, communicate to a field device bus). A plurality of field devices that can be connected) may include a plurality of field devices that are often communicatively connected to the process control device using a two-wire interface in a wired connection configuration or by wireless communication. Some field devices are configured to operate utilizing relatively simple commands and / or communications (eg, ON commands and OFF commands). Other field devices are more complex and require more commands and / or more communication information, which may or may not include simple commands. For example, more complex field devices may communicate analog values by digital communication superimposed on analog values, such as using a highway addressable remote transducer (“HART”) communication protocol. Other field devices can utilize full digital communication (eg, FOUNDATION fieldbus communication protocol).

  Some field devices (e.g., photoelectric or capacitive sensors) are implemented utilizing a three-wire architecture that allows such devices to be powered while simultaneously communicating. Such 3-wire field devices are typically connected to one or more I / O cards and connected to an external power source (and associated external fuse) to power the device.

  An exemplary apparatus for communicatively connecting a three-wire field device to a controller in a process control system is disclosed. An exemplary terminal block is disclosed that includes a first interface having three termination points for terminating each of three wires from a three-wire field device. The exemplary terminal block is capable of communicating with a three-wire field device using a first communication protocol, and using a second communication protocol different from the first communication protocol, Further included is a second interface that removably receives a first termination module that can communicate with the controller via a shared bus.

  Another exemplary terminal block is disclosed that includes a first interface that includes three wire termination points. Each wire termination point can terminate a corresponding wire out of three from a three-wire field device. The exemplary terminal block further includes a second interface for communicatively connecting to a shared bus of the termination panel substrate, the shared bus being communicatively connected to a controller of the process control system, the controller And communication between a three-wire field device.

  An exemplary apparatus is disclosed that includes a plurality of substrates on a termination panel that includes a shared bus. The exemplary apparatus further includes a terminal block communicatively connected to a first of the substrates. The terminal block can removably receive a first termination module that communicates with the control device via a shared bus. The terminal block includes a first interface for terminating each of the three wires from the three-wire field device, and communicatively connects the first termination module and the three-wire field device.

1 is a block diagram illustrating an example process control system. FIG. FIG. 2 is a detailed view of the exemplary marshalling cabinet of FIG. FIG. 4 shows a top view of an exemplary terminal block configured in accordance with the teachings disclosed herein. FIG. 3 shows a side view of an exemplary terminal block configured in accordance with the teachings disclosed herein. FIG. 3 shows an end view of an exemplary terminal block configured in accordance with the teachings disclosed herein. 3 is a side view of the exemplary terminal block of FIGS. 3A-3C with the exemplary termination module of FIGS. 1 and 2 partially inserted. FIG. FIG. 5 is a schematic diagram of exemplary wiring to the exemplary terminal block of FIGS. 3 and 4 installed in the exemplary marshalling cabinet of FIGS. 1 and 2 for a three-wire field device. FIG. 6 is a schematic diagram of the wiring of the 3-wire field device of FIG. 5 to a known terminal block installed in the exemplary marshalling cabinet of FIGS. 1 and 2. FIG. 5 is a schematic diagram of exemplary wiring to the exemplary terminal block of FIGS. 3 and 4 installed in the exemplary marshalling cabinet of FIGS. 1 and 2 of a two-wire field device.

  Software and / or firmware running on hardware between other components An exemplary apparatus and system is described below, but such a system is merely exemplary and should not be considered limiting Note that there is no point. For example, it is contemplated that any or all of these hardware, software and firmware components may be implemented with hardware only, software only, or any combination of hardware and software. Accordingly, although exemplary devices and systems are described below, one of ordinary skill in the art will readily appreciate that the embodiments presented herein are not the only way to implement such devices and systems.

  Exemplary process control systems include a control room (eg, control room 108 of FIG. 1), a process control region (eg, process control region 110 of FIG. 1), a termination region (eg, termination region 140 of FIG. 1), and One or more process areas (eg, process areas 114 and 118 of FIG. 1) are included. The process area includes a plurality of field devices (eg, control valves, control motors, control boilers, etc.) that perform operations related to the execution of a specific process (eg, chemical process, petroleum process, pharmaceutical process, pulp and paper process, etc.) Monitoring, measurement parameters, etc.). Due to harsh environmental conditions (eg, relatively high temperatures, airborne toxins, dangerous radiation levels, etc.), some process areas are not accessible to humans. Control rooms typically include one or more workstations in an environment that is securely accessible to humans. The workstation includes a user application that can be accessed by a user (eg, engineer, operator, etc.) to control the operation of the process control system, eg, by changing variable values, process control functions, and the like. The process control area includes one or more controllers that are communicatively connected to one or more workstations in the control room. By executing the process control strategy implemented via the workstation, the controller automates the control of field devices in the process area. An exemplary process strategy is to use pressure sensor field equipment to measure pressure and automatically send commands to the valve positioner based on the pressure measurement to open and close the flow valve. The termination area includes a marshalling cabinet that enables communication with field devices in the process area of the controller. In particular, the marshalling cabinet includes a plurality of termination modules that are utilized to marshal, organize, or route signals from a field device to one or more I / O cards that are communicatively connected to a controller. . The I / O card converts information received from the field device into a format corresponding to the control device, and converts information from the control device into a format corresponding to the field device.

  Known techniques utilized to communicatively connect field devices in a process control system to a control device are to each field device and control device (eg, process control device, programmable logic control device, etc.). And a separate bus (eg, wire, cable or circuit) between each I / O card communicatively connected. An I / O card converts or exchanges information communicated between a control device and a field device, thereby allowing different data types or signal types (eg, analog in (AI) data type, analog out (AO) data type). , Discrete in (DI) data type, discrete out (DO) data type, digital in data type and digital out data type) and a communicable connection of the controller to multiple field devices related to different field device communication protocols to enable. For example, an I / O card may include one or more field device interfaces configured to exchange information using a field device and utilizing a field device communication protocol associated with the field device. Different field device interfaces have different channel types (eg, analog in (AI) channel type, analog out (AO) channel type, discrete in (DI) channel type, discrete out (DO) channel type, digital in channel type and digital out type). Communication via the channel type). The I / O card also converts information (eg, voltage level) received from the field device into information (eg, pressure measurement value) that can be used by the control device to perform operations related to control of the field device. Can be converted. Known techniques require a bundle of wires or buses (eg, multi-core cables) to communicatively connect multiple field devices to an I / O card.

  Unlike these known techniques that utilize a separate bus to communicatively connect each field device to a corresponding I / O card, some known devices and methods allow multiple field devices to be connected to a termination panel. One bus (eg, conductive) that terminates at (eg, a marshalling cabinet) and is communicatively connected between the termination panel and the I / O card to communicatively connect the field device to the I / O card. The field device is communicably connected to the I / O card by using an optical communication medium, an optical communication medium, and a wireless communication medium. Such an apparatus and method is filed on Dec. 10, 2012, U.S. Patent No. 8,332,567, filed September 19, 2006, the entire disclosure of which is incorporated herein by reference. U.S. Pat. No. 8,762,618, U.S. Provisional Application No. 14 / 170,072 filed on January 31, 2014, and U.S. Provisional Application No. filed on January 8, 2015. 14 / 592,354. In essence, such a technique involves an exemplary general purpose I / O bus (eg, shared) that communicatively connects a plurality of termination modules to one or more I / O cards communicatively connected to a controller. Or a shared communication bus). Each termination module uses a respective field device bus (eg, analog bus or digital bus) from each field device that terminates on a terminal block that is communicatively connected to the corresponding termination module. One or more respective field devices are communicably connected. In some embodiments, the termination module is a CHARM (Characterizing Module) developed by Emerson Process Management. The termination module, for example, packetizes field device information and communicates the packetized information to the I / O card via the general-purpose I / O bus, thereby transferring the field device information from the field device to the field device bus. And receive field device information to the I / O card via a general-purpose I / O bus. One or more I / O cards can extract field device information received via the general purpose I / O bus and communicate the field device information to the control device. The controller can then communicate some or all of the information to one or more workstation terminals for later analysis. Similarly, the I / O card can packetize field device information from the workstation terminal and communicate the packetized field device information to a plurality of termination modules via a general-purpose I / O bus. Each termination module can then extract or depacket the respective field device information from the packetized communication received from the respective I / O card and communicate the field device information to the respective field device.

  Each termination module may be connected to a different type of field device that communicates using a different communication protocol. Thus, in addition to relaying information between the I / O card and the field device, the termination module is an I based on a first communication protocol associated with the field device and a second protocol associated with the general purpose I / O bus. Communicate with the corresponding field device using communication with the / O card. Thus, different termination modules may use different communication protocols to communicate with a particular field device, but all termination modules use the same communication protocol to communicate with the I / O card. In this way, communication back to the control device is greatly simplified.

  Communication with a number of field devices in the process control system is implemented using a two-wire architecture. For example, in a two-wire discrete input (DI) field device, to supply a field device contact input (e.g., power it and / or apply an electrical signal) and flow power when the contact is closed In addition, one wire is used. The second wire in the two-wire DI field device serves as an input to the process control system for the output signal of the field device (eg, providing feedback indicating whether the contact is open or closed) Used. Known terminal blocks provide an interface for connecting each of the two wires directly to the controller in the process control system and / or a termination module that then communicates with the controller as described above.

  In contrast, some field devices are three-wire field devices that have three wires to allow communication and provide power to operate the field device. For example, in a 3-wire DI field device, the first wire is utilized to provide field device and contact inputs (eg, to power and / or apply electrical signals thereto). The second wire of the 3-wire DI field device is particularly used to supply power to the field device. The third wire is used for the field device output signal which serves as an input to the process control system. A known terminal block can be communicatively connected to a 2-wire field device, but can be communicatively connected to a 3-wire DI field device without additional components and complexity. There is no terminal block. For example, a 3-wire field device may be wired to a known termination module for communication purposes via a known terminal (2-wire) platform, but the field device may also be externally connected to power the device. It must be wired to the power supply. Such wiring can include as many as five external wiring terminals in addition to two external wiring terminals for connecting the wires to the terminal block. That is, two wire terminals associated with the terminal block, two additional terminals associated with the external power source, and three more for allowing each of the three wires of the field device to be connected to the terminal block and the external power source. There are two terminals. Furthermore, the addition of the external power supply in this way also requires the use of an external fuse between the external power supply and the 3-wire field device for short circuit protection so that the energy of the normal power supply is not limited. These additional components and wiring requirements increase the cost and complexity of implementing a 3-wire field device. Some known systems use specially manufactured terminal blocks to facilitate the wiring of such 3-wire field devices. However, if an engineer or other facility personnel wants to change a component that senses signals coupled to such terminal blocks (eg, DI electronics), replace the terminal block and all associated wiring. And / or need to be removed. Furthermore, known terminal blocks for 3-wire DI field devices do not include fuses that still require additional components.

  An exemplary terminal block constructed in accordance with the teachings disclosed herein overcomes the above-described complexities to facilitate direct connection of a 3-wire field device to a process control system. In some embodiments, the terminal block disclosed herein includes three wire terminals, but each of the three wires of a three-wire DI field device directly connects the field device to a corresponding termination module. May be attached to that wire terminal. In some embodiments, a terminal block is communicatively connected to an external power source to provide power to each termination module that supplies the necessary power to the corresponding 3-wire field device. That is, in some embodiments, the terminal block provides an interface between the power source and the field device, thereby avoiding the need to individually connect each three-wire field device to an external power source. Further, in some embodiments, a fuse is incorporated in the terminal block disclosed herein to provide surge protection without the need for a separate external fuse. In some such embodiments, the fuse is replaceable. In some embodiments, the terminal block disclosed herein is a component (e.g., a corresponding component) that senses a signal without removing the terminal block and / or without wiring to a corresponding field device terminal block. It is possible to replace or change the termination module including the DI electronics contained within the termination module. As a result, initial wiring, maintenance and / or wiring updates for 3-wire DI field devices are greatly simplified with fewer components, saving time and money, The installation area of the entire system is reduced.

  Referring now to FIG. 1, an exemplary process control system 100 implementation is shown based on the teachings of US Pat. No. 8,332,567. Exemplary process control system 100 includes a workstation 102. The controller 104 is communicably connected via a bus or a local area network (LAN) 106, commonly referred to as an application control network (ACN). The LAN 106 may be implemented using any desired communication medium and protocol. For example, the LAN 106 may be based on a wired or wireless Ethernet communication protocol. However, any other suitable wired or wireless communication medium and protocol can be utilized. The workstation 102 may be configured to perform operations associated with one or more information technology applications, user interactive applications, and / or communication applications. For example, the workstation 102 may utilize other desired communication media (eg, wireless, wired, etc.) and protocol (eg, HTTP, SOAP, etc.) Applications related to process control and operations related to communication applications that allow communication with the system may be configured. The controller 104 may be one or more processes created by a system engineer or other system operator utilizing, for example, the workstation 102 or any other workstation, and downloaded and instantiated at the controller 104. It may be configured to perform a control routine or function. In the illustrated example, the workstation 102 is located in the control room 108 and the controller 104 is located in a process control area 110 separate from the control room 108.

  In the illustrated example, the exemplary process control system 100 includes field devices 112a-c in the first process region 114 and field devices 116a-c in the second process control region 118. In order to communicate information between the controller 104 and the field devices 112a-c and 116a-c, the exemplary process control system 100 includes a field junction box (FJB's) 120a-b and a termination panel or marshalling cabinet 122. Is provided. Each of the field junction boxes 120a-b routes signals from each of the field devices 112a-c and 116a-c to the marshalling cabinet 122. The marshalling cabinet 122 then marshalls (eg, organizes, groups, etc.) the information received from the field devices 112a-c and 116a-c, and the field device information is transmitted to each I / O of the controller 104. Route to cards (eg, I / O cards 132a-b and 134a-b). In the illustrated example, the marshalling cabinet 122 is also used to route information received from the I / O card of the controller 104 to each of the field devices 112a-c and 116a-c via the field junction boxes 120a-b. As described above, the communication between the control device 104 and the field devices 112a to 112c and 116a to 116c is bidirectional.

  In the illustrated example, the field devices 112a-c are communicably connected to the field junction box 120a, and the field devices 116a-c can communicate with the field junction box 120b via conductive, wireless, and / or optical communication media. Connected to. For example, field junction boxes 120a-b may include one or more electrical, wireless, and / or optical data transceivers for communicating with electrical, wireless, and / or optical transceivers of field devices 112a-c and 116a-c. May be provided. In the illustrated example, the field junction box 120b is communicably connected to the field device 116c. In other exemplary implementations, the marshalling cabinet 122 may be omitted, and signals from the field devices 112a-c and 116a-c are routed directly from the field junction boxes 120a-b to the I / O card of the controller 104. it can. In yet another exemplary embodiment, field junction boxes 120a-b may be omitted and field devices 112a-c and 116a-c may be directly connected to marshalling cabinet 122.

  The field devices 112a-c and 116a-c may be fieldbus-compatible valves, actuators, sensors, etc. In this case, the field devices 112a-c and 116a-c are digital using a well-known fieldbus communication protocol. Communicate via the data bus. Of course, other types of field devices and communication protocols may be used instead. For example, the field devices 112a to 112c and 116a to 116c may be Profibus, HART, or AS-i compatible devices that perform communication via a data bus using a known Profibus and HART communication protocol instead. It is. In some exemplary embodiments, field devices 112a-c and 116a-c can communicate information using analog or discrete communications instead of digital communications. Communication protocols can also be used for communication of information related to different data types. In some embodiments, one or more field devices 112a-c and 116a-c are two-wire field devices. In some embodiments, the one or more field devices 112a-c and 116a-c are three-wire field devices.

  Each of field devices 112a-c and 116a-c is configured to store field device identification information. The field device identification information may be a physical device tag (PDT) value, a device tag name, an electronic serial number, or the like that uniquely identifies each of the field devices 112a-c and 116a-c. In the illustrated example of FIG. 1, the field devices 112a to 112c store the field device identification information in the format of physical device tag values PDT0 to PDT2, and the field devices 116a to 116c store the field device identification information in the physical device tag values PDT3 to PDT5. Store in format. Field device identification information is stored or programmed in field devices 112a-c and 116a-c by a field device manufacturer and / or by an operator or engineer involved in the installation of field devices 112a-c and 116a-c. Also good.

  In order to route information related to field devices 112a-c and 116a-c in marshalling cabinet 122, marshalling cabinet 122 can communicate on marshalling cabinet 122 to a corresponding terminal block (eg, terminal block 206a in FIG. 2). A plurality of termination modules 124a-c and 126a-c. The terminal block holds and communicates with a first physical interface (eg, a wire termination point) to which wires from field devices 112a-c and 116a-c may be attached, and termination modules 124a-c and 126a-c. And a third physical interface that communicatively connects the terminal block to the marshalling cabinet 122 and the controller 104. In this way, communication between the control device 104, the termination modules 124a to c and 126a to c, and the field devices 112a to c and 116a to c becomes possible. Termination modules 124a-c are configured to marshal information associated with field devices 112a-c in first process area 114, and termination modules 126a-c are associated with field devices 116a-c in second process area 118. Configured to marshal information. As shown, termination modules 124a-c and 126a-c are communicatively connected to field junction boxes 120a-b via multi-conductor cables 128a and 128b (eg, multibus cables), respectively. In other exemplary implementations in which the marshalling cabinet 122 is omitted, termination modules 124a-c and 126a-c and corresponding terminal blocks can be installed in each of the field junction boxes 120a-b.

  The illustrated example of FIG. 1 is a point where each conductor (including one or more wires) of multi-conductor cables 128a-b communicates information uniquely associated with each of field devices 112a-c and 116a-c. A two-point configuration is shown. For example, the multi-conductor cable 128a includes a first conductor 130a, a second conductor 130b, and a third conductor 130c. In particular, the first conductor 130a is utilized to form a first data bus configured to communicate information between the termination module 124a and the field device 112a, and the second conductor 130b is coupled to the termination module 124b. A third conductor 130c is used to form a second data bus configured to communicate information with the field device 112b, and a third conductor 130c communicates information between the termination module 124c and the field device 112c. Is used to form a third data bus configured to: In another exemplary implementation that utilizes a multi-drop wiring configuration, each of termination modules 124a-c and 126a-c can be communicatively connected to one or more field devices. For example, in a multi-drop configuration, the termination module 124a can be communicatively connected via the first conductor 130a to the field device 112a and to another field device (not shown). In some exemplary embodiments, the termination module can be configured to communicate wirelessly with multiple field devices using a wireless mesh network. In some embodiments in which field devices 112a-c are three-wire field devices, multi-conductor cable 128a includes additional conductors for transferring power to field devices 112a-c.

  Each of termination modules 124a-c and 126a-c may be configured to communicate using a different data type than each of field devices 112a-c and 116a-c. For example, termination module 124a may include a digital field device interface that communicates with field device 112a using digital data, while termination module 124b includes an analog field device interface that communicates with field device 112b using analog data. May be included.

  To control I / O communication between the control device 104 (and / or the workstation 102) and the field devices 112a-c and 116a-c, the control device 104 includes a plurality of I / O cards 132a-b and 134a-. b. In the illustrated example, the I / O cards 132a-b are configured to control I / O communication between the controller 104 (and / or the workstation 102) and the field devices 112a-c in the first process area 114. Also, the I / O cards 134a-b are configured to control I / O communication between the controller 104 (and / or the workstation 102) and the field devices 116a-c in the second process area 118.

  In the illustrated example of FIG. 1, the I / O cards 132 a-b and 134 a-b are in the control device 104. In order to communicate information from the field devices 112a-c and 116a-c to the workstation 102, the I / O cards 132a-b and 134a-b communicate information to the controller 104, which in turn communicates information to the workstation. 102 to communicate. Similarly, to communicate information from the workstation 102 to the field devices 112a-c and 116a-c, the workstation 102 communicates information to the control device 104, which then transmits the information to the I / O cards 132a- b and 134a-b, and I / O cards 132a-b and 134a-b communicate information to field devices 112a-c and 116a-c via termination modules 124a-c and 126a-c. In other exemplary implementations, the I / O cards 132a-b and 134a-b are controlled by the controller so that the I / O cards 132a-b and 134a-b can communicate directly to the workstation 102 and / or the controller 104. It is possible to connect to a LAN 106 inside 104 so as to be communicable.

  In order to provide fault tolerant operation upon failure of either I / O card 132a and 134a, I / O cards 132b and 134b are configured as redundant I / O cards. That is, if the I / O card 132a fails, the redundant I / O card 132b controls and does the same operation that would otherwise be performed by the I / O card 132a. Similarly, the redundant I / O card 134b performs control when the I / O card 134a fails.

  In order to allow communication between termination modules 124a-c and I / O cards 132a-b, and between termination modules 126a-c and I / O cards 134a-b, termination modules 124a-c / O cards 132a-b are communicably connected via a first general purpose I / O bus 136a, and termination modules 126a-c are connected to I / O cards 134a-b by a second general purpose I / O bus 136b. It is connected so that communication is possible via. Unlike multi-conductor cables 128a and 128b, which use separate conductors or communication media for each of field devices 112a-c and 116a-c, each of the general purpose I / O buses 136a-b includes a plurality of field devices ( For example, information corresponding to the field devices 112a-c and 116a-c) is configured to communicate using the same communication medium. For example, the communication medium may be a serial bus, two-wire communication medium (eg, twisted pair) capable of communicating information related to two or more field devices using, for example, packet-based communication technology, multiplex communication technology, and the like. An optical fiber, a parallel bus, or the like may be used.

  General purpose I / O buses 136a and 136b are utilized to communicate information in substantially the same way. In the illustrated example, an I / O bus 136a is configured to communicate information between the I / O cards 132a-b and the termination modules 124a-c. The I / O cards 132a-b and the termination modules 124a-c can identify which information corresponds to which of the termination modules 124a-c, and which information is field devices. An addressing method is used so that each of the termination modules 124a-c can determine which one of 112a-c corresponds. If a termination module (eg, one of termination modules 124a-c and 126a-c) is connected to one of I / O cards 132a-b and 134a-b, the I / O card is automatic. Thus, the address of the termination module is obtained (for example, from the termination module), and information is exchanged with the termination module. In this way, it is not necessary to manually provide termination module addresses to the I / O cards 132a-b and 134a-b, and the termination modules 124a-c and 126a-c are respectively connected to the I / O cards 132a-b and 134a. The termination modules 124a-c and 126a-c can be communicably connected at any location of the buses 136a-b, without having to be individually wired to -b.

  It can be configured to communicate with field devices 112a-c and 116a-c using different data type interfaces (eg, different channel types), utilizing each of shared I / O buses 136a and 136b Thus, by providing termination modules 124a-c and termination modules 126a-c configured to communicate with I / O cards 132a-b and 134a-b, the illustrated example of FIG. Related to different field device data types (eg, data types or channel types used by field devices 112a-c and 116a-c and corresponding communication protocols) without having to be implemented on / O cards 132a-b and 134a-b Data I / O cards 132a-b and 134a Routing to b is possible. Thus, an I / O card having one interface type (eg, an I / O bus interface type for communicating via I / O bus 136a and / or I / O bus 136b) has a different field device interface type. It can communicate with multiple field devices.

  In the illustrated example, the I / O card 132 a includes a data structure 133, and the I / O card 134 a includes a data structure 135. The data structure 133 includes a field device identification number (eg, field device identification) corresponding to a field device (eg, field devices 112a-c) assigned to communicate with the I / O card 132a via the general purpose I / O bus 136a. Information). The termination modules 124a-c can determine whether a field device is incorrectly connected to one of the termination modules 124a-c using the field device identification number stored in the data structure 133. Data structure 135 includes a field device identification number (eg, field device identification) corresponding to a field device (eg, field devices 116a-c) assigned to communicate with I / O card 134a via general purpose I / O bus 136b. Information). Data structures 133 and 135 can be preconfigured via workstation 102 by an engineer, operator, and / or user during configuration time or operation of exemplary process control system 100. Although not shown, the redundant I / O card 132b stores the same data structure as the data structure 133, and the redundant I / O card 134b stores the same data structure as the data structure 135. Additionally or alternatively, data structures 133 and 135 can be stored on workstation 102.

  In the illustrated example, the marshalling cabinet 122 is shown located in a termination region 140 that is separate from the process control region 110. Substantially more communication media (eg, one of field devices 112a-c and 116a-c, respectively, or multiples thereof) to communicatively connect termination modules 124a-c and 126a-c to controller 104, respectively. By using the I / O buses 136a-b instead of a plurality of communication buses uniquely associated with a group limited along the drop segment, the control device without substantially reducing communication reliability It becomes easier to position 104 relatively far from marshalling cabinet 122 than in known configurations. In some exemplary embodiments, process control region 110 and termination region 140 can be combined such that marshalling cabinet 122 and controller 104 are located in the same region. In any case, the I / O cards 132a-b and 134a-b, the termination modules 124a-c, and the end modules 124a-c and the marshalling cabinet 122 and the control device 104 are placed in a different area from the process areas 114 and 118. 126a-c, and general purpose I / O buses 136a-b, can be isolated from harsh environmental conditions (eg, heat, humidity, electromagnetic noise, etc.) that may be associated with process areas 114 and 118. In this manner, termination modules 124a-c and 126a-c and I / O cards 132a-b and 134a-b are otherwise required to operate in the environmental conditions of process regions 114 and 118. Because the operational specification features (eg, shielding, more robust circuitry, more complex error checking, etc.) required to ensure reliable operation (eg, reliable data communication) are not required, field devices 112a- c and 116a-c compared to the manufacturing costs of the communication and control circuits, the design and manufacturing costs and complexity of termination modules 124a-c and 126a-c and I / O cards 132a-b and 134a-b It can be greatly reduced.

  Additional details and other exemplary implementations of exemplary marshalling cabinet 122 and termination modules 124a-c and 126a-c are described in US Provisional Application No. 8,332, the entire disclosure of which is incorporated herein by reference. , 567, U.S. Pat. No. 8,762,618, U.S. Provisional Application No. 14 / 170,072 and U.S. Provisional Application No. 14 / 592,354. Further details and other exemplary implementations may be utilized to communicatively connect the controller and I / O card.

  2 is a detailed view of an exemplary termination panel or marshalling cabinet 122 of FIG. In the illustrated example, the marshalling cabinet 122 includes a substrate 202 with socket rails 204. The illustrated example socket rail 204 is configured to receive terminal blocks 206a-c to which termination modules 124a-c may be communicatively connected. The marshalling cabinet 122 also includes an I / O bus transceiver 208 that communicatively connects the termination modules 124a-c to the general-purpose I / O bus 136a described above with reference to FIG. The I / O bus transceiver 208 may be implemented using transmitter and receiver amplifiers that condition the signals exchanged between the termination modules 124a-c and the I / O cards 132a-b. The marshalling cabinet 122 includes another general purpose I / O bus 210 that communicatively connects the terminal modules 124a-c (via terminal blocks 206a-c) to the I / O bus transceiver 208. In some embodiments, a plurality of substrates 202 may be communicatively connected to allow additional termination modules to be communicatively connected to the I / O transceiver 208. In some such embodiments, the substrates interconnect the I / O bus 210 across each substrate 202 such that the continuous substrate 202 is coupled to an underlying support frame 214 (eg, a DIN rail). A connector 212 is provided for connection.

  Design or installation by utilizing a shared communication interface (eg, I / O bus 210 and I / O bus 136a) to exchange information between I / O cards 132a-b and termination modules 124a-c Connections to field device I / O cards that route later in the process can be defined. For example, termination modules 124a-c can be communicatively connected to I / O bus 210 at various locations within marshalling cabinet 122 (eg, various terminal blocks 206a-c in different sockets of socket rail 204). Also, shared communication interfaces (for example, I / O bus 210 and I / O bus 136a) between I / O cards 132a-b and termination modules 124a-c are connected to I / O cards 132a-b and termination modules 124a-124. reducing the number of communication media to and from c (eg, the number of communication buses and / or wires), thereby being relatively greater than the number of known termination modules that can be installed in a known marshalling cabinet configuration Termination modules 124 a-c (and / or termination modules 126 a-c) can be installed in the marshalling cabinet 122.

  In order to provide power to termination modules 124 a-c and I / O bus transceiver 208, marshalling cabinet 122 includes a power supply circuit 218. In some embodiments, termination modules 124a-c utilize power from power supply circuit 218 to communicate with a field channel (eg, field device 112a-c in FIG. 1) or a communication channel or Power is supplied to the communication interface and / or power for operation is supplied to the field device. Additionally or alternatively, in some embodiments as shown in FIG. 2, each board 202 includes a local power bus 216 that may be connected to an external power source 220. The external power source 220 may be any suitable power source such as 24 volts direct current (VDC) or 120/230 volts alternating current (VAC). In some embodiments, termination modules 124a-c utilize power from external power supply 220 to provide power to a communication channel or communication interface and / or to provide operational power to field devices. By supplying power through the local power supply bus 216 in this way, it is not necessary to separately wire each three-wire field device requiring such power to an external power supply. In addition to cost savings due to fewer components, control system implementation costs are reduced by reducing the time required for system wiring and maintenance. In the illustrated example, the termination modules 124a-c may use power from either the internal power supply circuit 218 or the external power supply 220, but in either case, communication with the I / O cards 132a-b is still not possible. This is accomplished through the I / O bus 210 via the I / O bus transceiver 208. Whether termination module 124a-c uses power from internal power supply circuit 218 or external power supply 220 depends on the type or configuration of the terminal block used to interface termination module 124a-c with substrate 202. That is, in some embodiments, terminal block 206a includes a plurality of connectors (eg, substrate connector 310 of FIG. 3B) for electrically connecting terminal block 206a to substrate 202. In some embodiments, at least one connector connects the termination module 124a directly to the local power bus 216 of the board 202 (for powering) and at least one other connector connects the termination module 124a (communication). Connect directly to the general purpose I / O bus 210 of the board 202 (to enable).

  3A-3C show a top view, a side view, and an end view, respectively, of an exemplary terminal block 300 that may be similar or identical to the terminal blocks 206a-c of FIG. 4 shows a side view of the exemplary terminal block 300 of FIGS. 3A-3C with the exemplary termination module 124a of FIGS. 1 and 2 partially inserted into the slot 301 of the terminal block 300. FIG. As shown in the illustrated example of FIG. 4, the termination module 124 a is detachably connected to the terminal block 300 via the slot 301. More specifically, when the termination module 124a is inserted into the slot 301 of the terminal block 300, the termination module 124a is communicatively connected to and / or electrically connected to the corresponding contact 304 of the terminal block 300. A plurality of contacts 302 are included in the exemplary termination module 124a. In this way, the termination block 300 is suitable and connected to the substrate 202 (FIG. 2) and / or communicatively connected to a field device while selectively removing the termination module 124a and / or Alternatively, the terminal block 300 can be connected. In some embodiments, when the contact 304 of the terminal block 300 is electrically connected to the contact 302 of the termination module 124a, the termination module 124a is released or the termination module 124a is fixed in the installed position. A moving latch 305 is included in the terminal block 300. Additionally or alternatively, in some embodiments, latch 305 selectively secures termination module 124a in a partially installed position. In the partially installed position, termination module 124a prevents electrical contact between contacts 302, 304 of termination module 124a and terminal block 300 (similar to that shown in FIG. 4) while in slot 301. Properly retained. The wiring to the field device may thus be separated from the control system for ease of maintenance or to transfer power to the field device (eg, provided from the external power supply 220 of FIG. 2).

  In some embodiments, the terminal block 300 includes a plurality of board connectors 310 to communicatively connect the termination module 124a to the general purpose I / O bus 210 of FIG. As described above, in some embodiments, at least one board connector 310 connects termination module 124a to general purpose I / O bus 210 and provides power to termination module 124a and associated field devices from external power supply 220. To do so, at least one other board connector 310 connects the termination module 124 a to the local power bus 216. That is, unlike some known terminal blocks where all connectors to the board 202 connect the general purpose I / O bus 210 directly to the termination module, the example terminal block 300 includes the general purpose I / O bus 210 and the local power supply. A separate connection is provided for each of the buses 216. The board connector 310 may be implemented using any suitable interface including, for example, an insulated piercing connector, a knife connector, and the like. In this way, the termination module 124a can enable communication to the I / O bus 210 and transmission of power to the corresponding field device. More specifically, to allow communication of information between termination module 124a and I / O bus 210, board connector 310 connected to I / O bus 210 is also one of termination modules 124a. Alternatively, they are internally connected to a plurality of contacts 302. Similarly, the board connector 310 connected to the local power bus 216 is also connected to one or more different contacts 302 of the termination module 124a to allow transmission of power between the termination module 124a and the field device. And internally connected.

  In some embodiments, terminal block 300 receives conductive communication media (eg, bus wire) from a field device (eg, field device 112a of FIG. 1) (eg, via a moving cage clamp that is actuated by screw 308). A field device interface such as a wire termination point 306 for securing is provided. More particularly, in some embodiments, field device 112a is a three-wire DI field device. In some such embodiments, each of the three wire termination points 306 of the terminal block 300 can receive one of the three wires from the three-wire field device. When termination module 124a is removably connected to terminal block 300, termination point 306 is communicatively connected to one or more contacts 302 of termination module 124a, between termination module 124a and field device 112a. Communication of information. Further, in some embodiments, termination point 306 is communicatively connected to one or more contacts 302 to transfer power between termination module 124a and field device 112a based on power from external power source 220. Enable.

  In other exemplary implementations, the terminal block 300 may include any other suitable type of field device interface (eg, socket) instead of the terminal screw 308. Also shown is one field device interface (eg, termination point 306 having screws 308), but the terminal block 300 is configured to communicatively connect a plurality of field devices to the termination module 124a. More field device interfaces may be provided.

  For the exemplary termination block 300 that is electrically connected to the local power bus 216, a short circuit associated with the corresponding termination module 124a and the corresponding field device occurs, and the other terminal blocks on the substrate 202 are otherwise There is a possibility to transfer power from the termination module. Thus, in the illustrated example, termination block 300 includes a fuse 312 that protects other termination modules (in other terminal blocks) from losing power. In some embodiments, the fuse is replaceable. In this way, the cost of obtaining and wiring a separate external fuse is reduced. Further, by incorporating the fuse 312 into the terminal block 300, the installation area of the entire system is reduced.

  FIG. 5 is a schematic diagram of an exemplary implementation of the exemplary terminal block 300 of FIGS. 3 and 4 wired to a three-wire field device 502 (eg, corresponding to the field device 112a of FIG. 1). In some embodiments, field device 502 is a discrete input (DI) field device such as a photoelectric or capacitive sensor, a switch or other such DI device that requires power for operation. In the illustrated example, the terminal block 300 supplies power 504 from the external power source 220. The terminal block 300 is communicably connected to the substrate 202. Further, in the illustrated example of FIG. 5, U.S. Provisional Application No. 8,332,567, U.S. Pat. No. 8,762,618, U.S. Provisional Application No. 14 / 170,072 and U.S. Provisional Application No. 14 / 592,354 to allow communication between field device 502 and controller 104 (FIG. 1), as described in more detail. In addition, the terminal block 300 is communicatively connected to a termination module 124 a that provides isolation and control circuitry 506.

  As shown in the illustrated example of FIG. 5, each of the three wires of the field device 502 is directly attached to one of the three termination points 306 of the terminal block 300. Signal communication and power transfer is accomplished through the internal wiring and design of the terminal block 300 (including the board connector 310) associated with the termination module 124a and the board 202 (which may be connected to the external power supply 220). Further, in some embodiments, the terminal block 300 includes a fuse 312 embedded in the terminal block 300 between the termination point 306 and the substrate 202 (for supplying power) for short circuit protection.

  For comparison, FIG. 6 shows a schematic implementation of a 3-wire DI field device 502 wired to a termination module 124a utilizing a known terminal block 602 configured to handle a shared 2-wire architecture. Show. As described above, an external power supply is required to implement the 3-wire field device. Unlike the illustrated example of FIG. 5, the terminal block 602 of FIG. 6 is not provided for supplying power through the substrate 202. As a result, the external power source 604 must be separately connected to the 3-wire field device 502. In such a scenario, three intermediate terminals 606 may be required to interface the 3-wire field device 502 with both the external power source 604 and the terminal block 602. In addition, additional wires 608 may need to be attached to terminal block 602 and electrically connected to external power source 604 via two additional terminals 610. Furthermore, for the external power supply 604 wired inside, an external fuse 612 for short circuit protection is required. Each of the terminations 606, 610, wires 608 and fuses 612 shown in FIG. 6 add cost and complexity for system control that can be avoided by use of the exemplary terminal block 300 shown in FIG. And separate components. In addition, the exemplary implementation shown in FIG. 5 has a much larger footprint than that shown in FIG. 6 because additional components are either excluded or incorporated into the terminal block 300. Narrow.

  In order to provide the exemplary power illustrated in FIG. 5, the external power source 220 must still be routed to the substrate 202, but in some embodiments this wiring is communicatively connected to the substrate 202. It only needs to be done once for all field devices. In some embodiments, the substrate 202 holds up to 12 terminal blocks and corresponding termination modules. In contrast, using known techniques, each additional three-wire field device must be individually connected to an external power source 604, as shown in FIG. 6, thereby further controlling system settings and Maintenance costs and complexity increase.

  FIG. 7 illustrates an exemplary implementation of the exemplary terminal block 300 of FIGS. 3 and 4 wired to a two-wire field device 702 (eg, which may be similar or identical to the field device 112a of FIG. 1). FIG. Although the terminal block 300 may be advantageously used to communicatively connect to a 3-wire field device as shown in FIG. 5, in some embodiments, the terminal block 300 may also be used as shown in FIG. May be used to connect to a shared two-wire field device in a communicable manner. In some embodiments, the two-wire field device 702 is powered via an external power source 220. As a result, the exemplary terminal block 300 disclosed herein may be utilized to communicatively connect either a 2-wire field device or a 3-wire field device to a process control system.

Although certain exemplary devices are disclosed herein, the scope of this patent is not limited thereby. In contrast, the patent covers all methods, devices, and products that are properly included within the scope of the claims.

Claims (20)

A first interface having three termination points for terminating each of the three wires from the three-wire field device;
The first communication protocol can be used to communicate with the three-wire field device, and the second communication protocol different from the first communication protocol can be used to control the terminal panel via the shared bus. A second interface for removably receiving a first termination module capable of communicating with the device;
Terminal block with   The second interface can removably receive a second termination module instead of the first termination module, and the second termination module is different from the first and second communication protocols. The terminal block according to claim 1, wherein communication is performed with the second field device via the first interface using a communication protocol of No. 3.   The terminal block according to claim 1, wherein the first termination module is replaceable with a second termination module, and the first interface is communicatively connected to the three-wire field device.   The terminal block according to claim 1, wherein the first termination module is replaceable with a second termination module and is communicably connected to the shared bus of the termination panel.   The power supply bus of the terminal panel further includes a third interface electrically connected to the power supply bus, and the power supply bus separate from the shared bus supplies power to the three-wire field device from an external power supply. The terminal block according to 1.   The terminal block according to claim 5, further comprising a fuse disposed between the first interface and the third interface for short circuit protection.   The terminal block according to claim 1, wherein the three-wire field device is a discrete input field device.   The terminal block of claim 1, wherein the first termination module can communicate with the two-wire field device when a two-wire field device is wired to the first interface. A first interface comprising three wire termination points, each of said wire termination points terminating a corresponding wire of three from a three-wire field device;
A second interface communicatively connected to a shared bus on the board of the termination panel, wherein the shared bus is a process control system to enable communication between the controller and the three-wire field device The second interface communicatively connected to the control device of
Terminal block with   The control device can communicate with the three-wire field device using a first communication protocol and uses a second communication protocol different from the first communication protocol via the shared bus. The terminal block according to claim 9, further comprising a third interface that removably receives a termination module capable of performing the following communication.   The termination module is replaceable with a second termination module, and at least one of the second interfaces is communicatively connected to the shared bus, or the three wires of the three-wire field device are The terminal block according to claim 10, wherein the terminal block is communicably connected to the first interface.   And further comprising a second interface communicatively connected to a local power bus of the substrate and a first of the three wires, via the first of the three wires. The terminal block according to claim 9, wherein the local power bus is electrically connected to an external power source to supply power to the three-wire field device.   The terminal block according to claim 12, further comprising a fuse disposed between the first interface and the second interface.   The terminal block according to claim 9, wherein the three-wire field device is a discrete input field device. Multiple boards on a termination panel with a shared bus; and
A terminal block communicably connected to a first one of the boards, the terminal block removably receiving a first termination module communicating with a control device via the shared bus, The terminal block comprising a first interface for terminating each of the three wires from the three-wire field device to communicatively connect the first termination module and the three-wire field device;
A device comprising:   16. The apparatus of claim 15, wherein the first termination module is replaceable with a second termination module, and the first interface is communicatively connected to the three-wire field device.   16. The first termination module is replaceable with a second termination module, and the terminal block is communicably connected to the shared bus via the first board of the boards. The device described in 1.   Each of the substrates is a separate local power bus different from the shared bus and the terminal block electrically connected to the local power bus of the first substrate of the substrates, The terminal block for supplying power to the three-wire field device from an external power source electrically connected to the local power bus of the first substrate of the substrates. apparatus.   The apparatus of claim 18, wherein the terminal block comprises a fuse disposed between the local power bus of the first board of the boards and the first interface. The apparatus of claim 15, wherein the first termination module can communicate with the two-wire field device when a two-wire field device is wired to the first interface.